1. Field of the Invention
This invention relates to a canalicular implant adapted to be utilized in the treatment of a human eye having a deficiency of tears and more specifically relates to a canalicular implant having means defining a tapered section at one end thereof which slopes in the direction towards the first end and means defining a collapsed flared section at a second end thereof.
This invention also relates to a method for treating external eye conditions due to a deficiency of tears utilizing the canalicular implant having a collapsible flared section at one end thereof.
2. Description of the Prior Art
It is known in the art that certain eye problems are related to the volume of tears on the surface of the eyes. Certain of these problems include dry eyes, corneal ulcer, conjunctivitis, blepharitis, contact lens problems and many other external eye diseases.
One method for treating for a deficiency of tears is disclosed in U.S. Pat. No. 4,660,546, wherein the inventor is the same inventor of the present invention. U.S. Pat. No. 4,660,546 discloses a method for treating external human eye conditions due to a deficiency of tears which includes the step of temporarily blockading the canaliculus of the patient and observing over a preselected period of time the response of the patient's eye to the temporary blockage and to determine if any improvement in the eye condition has been achieved in response to the occlusion. If an improvement in eye condition is noted, an implant is placed within the horizontal portion of at least one of the canaliculi of the patient. A temporary blockading of the canaliculus is performed by placing a dissolvable, removable element, which may be in the form of a collagen material or other dissolvable material such as, for example, catgut, in the canaliculus. Unless removed shortly after insertion, the dissolvable implant is absorbed by the body in approximately a two week period. A determination is first made if the canaliculus blockage results in an improvement in the eye condition or other conditions caused by related nasal congestion warranting permanent blockage of the canaliculus, for example, the patient will respond to a partial 60% to 80% retention of constant tears. If permanent blockage of the canaliculus is warranted, U.S. Pat. No. 4,660,546 discloses that the permanent blocking of the canaliculus is performed by utilizing a permanent implant. U.S. Pat. No. 4,660,546 discloses that the permanent implant is fabricated of a nonabsorbable or non-dissolvable material and is in the form of a cylindrically shaped central body having a tapered end or an end of reduced diameter to facilitate the implantation of the implant into and for removal of the implant from the canaliculus. Both the temporary collagen implant or other dissolvable material and the permanent implant disclosed in U.S. Pat. No. 4,660,546 are in the form of a cylindrically shaped central member having a predetermined diameter which may terminate at one end in a tapered end and which reduces in diameter as it slopes away from the central member to form a tapered tip to facilitate insertion of the implant through the punctum, throught vertical canaliculus and into the horizontal portion of the canaliculus.
U.S. Pat. No. 4,461,295, wherein the inventor thereof is the same as the inventor of the present invention, discloses another treatment method which is a method for lasar punctal occlusion. It is known in the art that punctal occlusion has been proven to be an effective way of treating patients which conditions such as sinusitis, hay fever, middle eye infection (chronic), post nasal drip, front headache and other such conditions. The treatment method disclosed by U.S. Pat. No. 4,461,295 includes the use of a temporary suture to stitch the tear drainage canals of the eyes closed to determine if a greater tear volume on the surface of the eyes would improve certain eye problems. This diagnostic procedure has become known in the art as the Herrick Stitch Test. The Herrick Stitch Test is performed by anesthetizing the local area around the lower or upper punctum of the eye. A stitch is carefully placed to occlude the punctum by an eye surgeon utilizing magnification of the eye. After a preselected period of time using the Herrick Stitch Test, the eye surgeon determines if the eye condition has improved, if so, then the eye surgeon permanently closes the punctum by using an ARGON lasar. The punctum may be reopened at a later time if excess tearing is experienced. The reopening of the punctum can be performed by surgical and lasar techniques, all as disclosed in U.S. Pat. No. 4,461,295.
It is also known in the art to utilize other plugs and or techniques for occluding the punctum. One plug device which is known in the art is referred to as a punctum plug which is described in an article by Jerre M. Freeman, M.D., entitled "The Punctum Plug: Evaluation of a New Treatment for the Dry Eye" which appeared in the publication of the transcripts of the Americal Academy of Ophthalomology and Optometry, pages OP-874 through OP-879 (hereinafter referred to as the "Freeman Reference"). In addition, the same punctum plug is disclosed and described in U.S. Pat. No. 3,949,750.
The punctum plug disclosed in the Freeman Reference and in U.S. Pat. No. 3,949,750 is a plug which is adapted to be inserted into the upper and/or lower punctal openings of the eye to block or occlude the punctum. The punctum plug of Freeman is a rod-like plug formed with an oversized tip or barb portion that dialates and blockingly projects into the vertical canaliculus. The punctum plug has a smaller neck or waist portion around which the punctum sphincter ring tightens. The punctum plug has relatively large, smooth head portion which rests on top of the punctal opening and prevents the plug from passing down into the canaliculus. The smooth head portion is designed to be domed shaped to permit the head to rest in the lacrimal lake and against the conjunctiva and cornea with little irritation. The head portion functions to prevent the punctum plug from passing into the horizontal portion of the canaliculus. The punctum plug of Freeman is subject to being inadvertantly removed from the eye by the patient.
It is also known in the art to provide for a temporary closure of the punctum by heat using a light cautery around and in the punctal opening. The punctal closure procedure is disclosed in an article entitled "Diagnosis and Treatment of Keratoconjunctivitis Sicca" which appeared in a symposium on medical and surgical diseases of the cornea, transactions of the New Orleans Academy of Opththalmology in 1980 at page 43 wherein the authors thereof were Jose I. Barraquer, M.D. and eight other authors (hereinafter referred to as the "Barraquer Reference"). The Barraquer Reference further discloses that other treatment methods of temporarily closing the punctum include use of gelatin plugs, cyanoacrylate adhesives and diathermy. The use of intracanalicular gelatin implants for treatment of eye conditions is described in an article entitled "INTRA-CANALICULER GELATIN IMPLANTS IN THE TREATMENT OF KERATO-CONJUNCTIVITIS SICCA" by Wallace S. Foulds which appeared in the Brit J. Ophthal (1961) in Volume 45 at pages 625 through 627, inclusive, (the "Foulds Reference"). The Foulds Reference discloses that occlusion of the lacrimal puncta can be performed by use of and insertion of a fine, water soluble gelatin rod into the punctal openings. The gelatin rod is formed from pure powdered gelatin to which a small quantity of distilled water has been added and is heated in a water bath until the gelatin dissolves and a thick gel results. By dipping a cold glass rod into the so prepared gelatin, and withdrawing the same, fine solid rods of gelatin were formed. The so formed gelatin rods were then inserted into the canaliculi to provide a temporary blockage. As such, the gelatin rod implants, although very fragile, provide an alternate known means for temporarily blocking the canaliculus. If an improvement in eye condition is obtained, then permanent closure of the canaliculi may be warranted.
It is known in the art that a Schirmer's test can be utilized to measure gross tear secretion. If the results of the Schirmer tear secretion test discloses that an insufficient portion of the tear secretion is retained on the eyes, a temporary or permanent occlusion of the canaliculi may prove helpful to improving the above described external eye conditions.